Rotary regenerative heat exchanger



(3- A. LYLE ROTARY REGENERATIVE HEAT EXCHANGER March 31, 1964 2 Sheets-Sheet 1 Filed Dec. 29, 1959 Char/e; 4 Zy/e 10.

AGE/Y7 March 31, 1964 c. A. LYLE ROTARY REGENERATIVE HEAT EXCHANGER 2 Shets-Sheet 2 Filed Dec. 29. 1959 United States Patent 3 126 946 RorAnY nnonnnniirrvn HEAT nxcnanonn Charles A. Lyle, Wellsville, N.Y., assignor, by mesne assignments, to Combustion Engineering, Inc, a stock corporation of Delaware Filed Dec. 29, 1959, Ser. No. 862,636 9 Claims. (Ci. 165-7) from hot exhaust gases to cool compressed air being supplied to a combustion chamber of a boiler or gas turbine.

In heat exchange apparatus of this type, heat from the hot exhaust gases is first directed through one passageway of a rotating drum carrying heat absorbent material while cool air for combustion is directed through a spaced passageway thereof. As heat from the hot gases is transferred to the heat absorbent material, and as the hot heat absorbent material is rotated into the air passageway, the heat or" the waste gases is indirectly transferred to the cooler combustion air flowing therethrough.

In gas turbine practice, it is usual for air to pass through a heat exchanger after delivery from a compressor where it has been compressed to a relatively high pressure, while hot gases passing through a spaced portion of the heat exchanger have just been exhausted from the turbine and are therefore at a much lower pressure than the air. As the rotor of the heat exchanger is subjected to a substantial thermal and pressure gradient, its parts become distorted in such a manner that it becomes exceedingly diificult to seal the high from low pressure fluid, and air that has been compressed at great expense is lost to the system.

Various attempts have been made to improve sealing conditions by either eliminating deformation of the rotor and rotor housing or by providing adjustable seals that accommodate limited distortion thereof. The chief object of this invention is not only to provide an adjustable seal but to provide a novel arrangement of rotor and rotor housing that permits an effective sealing arrangement throughout a wide range of thermal deformation.

Further objects will become more readily apparent from a reading of the description in connection with the accompanying drawings.

Referring to the accompanying diagrammatic draw ings, FIGURE 1 shows a longitudinal sectional elevation of a rotary regenerative heat exchanger involving my invention.

FIGURE 2 shows a transverse sectional view as seen from line 22 of FIGURE 1.

FIGURE 3 is an enlarged detail showing abutting sealing shoes.

FIGURE 4 is an enlarged detail showing the cooperative relationship of abutting sealing shoes.

FIGURE 5 is a longitudinal sectional elevation of a modified form of rotary regenerative heat exchanger inthe spaced flow of a high pressure fluid to be heated.

Each of the openings 16, 18, 20 and 22 normally asice sumes the form of an arcuate slot having an imperforate portion 23 between ends thereof that serves to separate the spaced fluids.

A rotor containing a mass of heat absorbent material 24 is carried within the housing on a rotor post 26 that is supported at opposite ends of the housing by a thrust bearing 23 and a radial support bearing 32 that permits unrestrained elongation and contraction of the rotor post within the housing. The rotor comprises a cylindrical shell 34% that is carried concentrically about the rotor post by a series of radial partitions 36 that extend therebetween to provide sectorial compartments 39 in which the heat exchange material is carried.

The rotor is turned on its axis by a drive motor 37 connected to the rotor post at the end lying adjacent the thrust bearing 2?. The rotor support bearings and drive motor are mounted upon any suitable support structure having the required strength characteristics.

A series of openings 38 in opposite ends of each compartment are adapted to sequentially coincide with the spaced openings of the housing in order that fluids passing thru the housing are directed through the heat exchange material within the several compartments of the rotor. Sealing means shown generally at 42 are arranged around each opening 38 in the rotor shell and adapted to extend outward to the housing 10 to restrict fluid flow to its predetermined channels.

Each sealing means 4-2 comprises essentially an extensible member 44 and a sealing shoe 46 that is held in sealing relationship with the housing. The extensible member 44- shown in the drawing is a simple annular bellows member that is secured at its outer end to a rectan gular sealing shoe 46 in such a manner that a portion of the sealing shoe lies radially within the central portion of the extensible member as seen in FIGURE 3. This provides an effective area against which the pressure fluid within the rotor may act to force the sealing shoe 46 into sealing engagement with the rotor housing. The sealing shoes are provided with an arcuate outer surface that fits the curvature of the housing such that the sealing shoes together provide a composite annular surface encircling the rotor and bridging the space between the rotor and rotor housing. A flexible packing means 47 fitting grooved portions of adjacent sealing shoes links adjacent shoes into a continuous surface permitting limited relative movement therebetween.

A modified form of the invention is shown in FIGURE 5. Here the end of the rotor supported by the radial support bearing is provided with sealing means 42 of the type described for FIGURE 1. The opposite end of the rotor adjacent the thrust bearing 28 is however provided with conventional openings 54 and 56 which are adapted to permit the axial flow of high and low pressure fluids to and through the compartments of the rotor. The end plate 52 is formed from heavy plate material having unusual strength to resist distortion of the rotor and rotor housing. Since there is no thermal gradient across plate 52 there is no thermal deformation, and its strength precludes deformation in accordance with the deformation of other housing members. The thrust bearing 28 maintains a predetermined spacing relation between the end of rotor shell 34 and the adjacent face of end plate .52, while the opposite end of the rotor supported by the support bearing 32 is free to move axially in accordance with varying thermal conditions.

The heavy end plate 52 is positioned at the end of the rotor commonly known as the hot end which lies adjacent the inlet for the heating fluid Conventional sealing means 555 aifixed to the end of the rotor are adapted to extend toward the adjacent surface of end plate 52 to provide adequate sealing at the fixed end of the rotor. The opposite or cold end of the rotor that is carried sealing shoe.

2% by the radial support bearing 32 is constructed in the manner previously outlined with a series of radially extensible sealing means 42 mounted around openings 38 in the rotor shell adapated to extend radially outward to the inner face of the rotor housing.

The extensible members 44 are preferably set to bias the sealing shoes 46 lightly against the adjacent surface of the rotor housing under conditions of no load. When the fluid pressure in the housing is brought up to normal operating conditions the pressure of the fluid within the extensible member will act against the surface area of the sealing shoe lying radially within the extensible member while the pressure of the fluid in the plenum chamber 14 will act against the surface area of the sealing shoe lying outside the extensible member to force the sealing shoe il'lltO a sealing relationship with the inner surface of the rotor housing. The pressure of the plenum chamber may be controlled by a valve in the housing 10. If left closed, the plenum pressure attains a maximum and thus provides a significant force against the sealing shoe 46, while if vented through valve 25, the plenum pressure may be neutralized to provide no net force against the Various intermediate settings of valve 25 may be utilized to provide the desired plenum pressure ar61d the desired net sealing force against the sealing shoe 4 While my invention has been described with reference to the embodiments illustrated in the drawings, it is evident that various changes may be made without departing from the spirit of the invention, and it is intended that all matter contained in the above description or shown in the accompan u'ng drawings shall be interpreted as illustrative and not in a limiting sense.

What I claim is:

1. Rotary regenerative heat exchange apparatus having a rotor including a cylindrical rotor shell, a rotor post centrally located within said rotor shell, bearing means supporting the rotor for rotation about its axis, radial partitions extending between the rotor post and rotor shell to provide a series of sector-shaped compartments therebetween, axially spaced openings in the arcuate wall of each compartment for the passage of fluid therethrough, a mass of heat absorbent material carried by the compartments of the rotor, means for rotating the rotor about its axis, a cylindrical housing including end plates at opposite ends thereof enclosing the rotor in spaced relation to provide an annular plenum chamber therebetween, a pair of circumferentially spaced openings at each end of the housing axially aligned with the openings in the rotor shell and arranged to direct a heating fluid and a fluid to be heated through spaced compartments of the rotor, and sealing means carried by the rotor around a plurality of the openings therein and extending radially outward through the plenum chamber into a sealing relationship with the rotor housing whereby rotation of the rotor about its axis will sequentially place each compartment of the rotor in communication with the openings for the heating fluid and the fluid to be heated in said housing.

2. Rotary regenerative heat exchange apparatus as defined in claim 1 wherein said sealing means enclosing the openings in the rotor comprises radially extensible duct means, and a sealing shoe with an arcuate outer surface abutting the inner periphery of the cylindrical rotor housing affixed to the radially outer end of each radially extensible duct, said sealing shoe having a surface area lying radially within the extensible sealing means whereby fluid pressure acting against said surface area produces a force suflicient to move the sealing shoe against the inner surface of the housing.

3. Rotary regenerative heat exchange apparatus having a rotor including a cylindrical rotor shell, a rotor post centrally positioned within said shell, radial partitions extending from the rotor post to the rotor shell to provide a series of sector-shaped compartments therebetween, axially spaced openings in the arcuate wall of each sector-shaped compartment for the passage of fluid therethrough, a mass of heat absorbent material carried in each compartment of the rotor, means for rotating the rotor about its axis, a cylindrical housing enclosing the rotor in spaced relation to provide a plenum chamber therebetween, end plates at opposite ends of said housing, a pair of circumferentially spaced inlet and outlet ports in each end of said housing axially aligned with the openings of the rotor shell, a thrust bearing at one end of the housing supporting the rotor in axially fixed relation to its adjacent end plate, a radial guide bearing at the opposite end of said housing supporting the rotor against radial displacement while permitting axial movement therethrough and a varying relationship between the corresponding end of the rotor and its adjacent end plate, and radially extensible sealing means secured to the rotor shell around each opening therein and extending into sealing relationship with the corresponding ports in the housing whereby fluid from the inlet ports is directed through the compartments of the rotor.

4. Rotary regenerative heat exchange apparatus having a rotor including a cylindrical rotor shell, a rotor post centrally positioned within said shell, radial partitions extending from the rotor post to the rotor shell to provide a series of sector-shaped compartments therebetween, a mass of heat absorbent material carried in each compartment of the rotor, means for rotating the rotor about its axis, plate means enclosing one end of the rotor to provide an imperforate end wall for each compartment, an opening into the arcuate outer wall of each compartment of the rotor adjacent said plate means, a cylindrical housing enclosing said rotor shell in spaced relation to provide a plenum chamber therebetween, a pair of circumferentially spaced openings in the cylindrical wall of said housing axially aligned with the openings in said rotor shell arranged to permit the flow of a heating fluid and a fluid to be heated through aligned openings, end plates at opposite ends of said housing including an imperforate end plate adjacent the plate means on the rotor and an end plate with spaced apertures at its opposite end, a thrust bearing supporting the rotor in axially fixed relation with respect to the apertured end plate, a radial guide bearing at the axially spaced end of the rotor encircling the rotor post to preclude radial displacement of the rotor post throughout wide ranges of axial distortion, and extensible sealing means encircling the openings in the outer wall of each compartment extending radially therefrom into a sealing relation with said housing whereby rotation of the rotor about its axis will sequentially align the openings of the rotor with the circumferentially spaced openings of the housing so as to permit communication therebetween.

5. Rotary regenerative heat exchange apparatus having a rotor including a cylindrical rotor shell, a rotor post centrally positioned within said shell, radial partitions extending from the rotor post to the rotor shell to provide a series of sector-shaped compartments therebetween, a mass of heat absorbent material carried in each compartment of the rotor, means for rotating the rotor about its axis, plate means enclosing opposite ends of the rotor shell to form end walls for each compartment, an opening in each end of the arcuate outer wall of each of said compartments arranged to permit the flow of fluid therethrough, a cylindrical housing enclosing the rotor shell in spaced relation to provide a plenum chamber therebetween, a pair of circumferentially spaced openings at each end of the housing axially aligned with the openings of the rotor shell adapted to permit alignment thereof when the rotor is rotated about its axis, end plates at opposite ends of said housing spaced from the plate means enclosing ends of the rotor shell, radially extensible duct means fixed to the outer wall of the rotor shell around each opening therein, an apertured sealing shoe aflixed to the radially outer end of each extensible duct means having an arcuate outer surface that conforms to the surface of the rotor housing, said extensible duct afiixed to its sealing shoe intermediate its outer and inner edges to provide an effective surface area lying radially within the periphery of the extensible sealing means and an effective surface area lying radially outside the periphery of the extensible sealing means against which the pressure of said fluids may act to force the sealing shoe into a sealing relationship with the inner surface of the housing.

6. Regenerative heat exchange apparatus as defined in claim 5 including an opening in the cylindrical housing adapted to vent fluid from the plenum chamber.

7. Regenerative heat exchange apparatus as defined in claim 5 including an opening in the cylindrical housing having a control valve therein adapted to bleed the plenum chamber to provide a predetermined pressure therein.

8. Regenerative heat exchange apparatus as defined in claim 5 wherein the sealing shoes are of rectangular configuration with laterally adjacent sides lying in abutment E to provide a composite annular sealing means extending around the rotor.

9. Regenerative heat exchange apparatus as defined in claim 8 including a flexible packing strip overlapping adjacent sides of said sealing shoes to provide a continuous surface therefor.

References Cited in the file of this patent UNITED STATES PATENTS 2,347,829 Karlsson et al May 2, 194-4 2,665,120 Blomquist Jan. 5, 1954 2,738,958 Hodge Mar. 20, 1956 2,766,970 Horn Oct. 16, 1956 2,863,644 Fallon Dec. 9, 1958 2,942,857 Lyle et a1 June 28, 1960 FOREIGN PATENTS 798,698 Great Britain July 23, 1958 

1. ROTARY REGENERATIVE HEAT EXCHANGE APPARATUS HAVING A ROTOR INCLUDING A CYLINDRICAL ROTOR SHELL, A ROTOR POST CENTRALLY LOCATED WITHIN SAID ROTOR SHELL, BEARING MEANS SUPPORTING THE ROTOR FOR ROTATION ABOUT ITS AXIS, RADIAL PARTITIONS EXTENDING BETWEEN THE ROTOR POST AND ROTOR SHELL TO PROVIDE A SERIES OF SECTOR-SHAPED COMPARTMENTS THEREBETWEEN, AXIALLY SPACED OPENINGS IN THE ARCUATE WALL OF EACH COMPARTMENT FOR THE PASSAGE OF FLUID THERETHROUGH, A MASS OF HEAT ABSORBENT MATERIAL CARRIED BY THE COMPARTMENTS OF THE ROTOR, MEANS FOR ROTATING THE ROTOR ABOUT ITS AXIS, A CYLINDRICAL HOUSING INCLUDING END PLATES AT OPPOSITE ENDS THEREOF ENCLOSING THE ROTOR IN SPACED RELATION TO PROVIDE AN ANNULAR PLENUM CHAMBER THEREBETWEEN, A PAIR OF CIRCUMFERENTIALLY SPACED OPENINGS AT EACH END OF THE HOUSING AXIALLY ALIGNED WITH THE OPENINGS IN THE ROTOR SHELL AND ARRANGED TO DIRECT A HEATING FLUID AND A FLUID TO BE HEATED THROUGH SPACED COMPARTMENTS OF THE ROTOR, AND SEALING MEANS CARRIED BY THE ROTOR AROUND A PLURALITY OF THE OPENINGS THEREIN AND EXTENDING RADIALLY OUTWARD THROUGH THE PLENUM CHAMBER INTO A SEALING RELATIONSHIP WITH THE ROTOR HOUSING WHEREBY ROTATION OF THE ROTOR ABOUT ITS AXIS WILL SEQUENTIALLY PLACE EACH COMPARTMENT OF THE ROTOR IN COMMUNICATION WITH THE OPENINGS FOR THE HEATING FLUID AND THE FLUID TO BE HEATED IN SAID HOUSING. 